An interesting list OP! Personally I’d narrow it down to Hazel, Frida, Fern and Nancy.
Madeline - OK, a little dull and I dislike Maddy as a nickname (the one I know gets Madz, which imo is even worse!) Prefer Madeleine spelling.
Hazel - lovely. Nice warm, earthy vibe and nature/colour associations.
Frida - love this. Strong, feisty and unfrilly, for me it has a cool Scandi vibe
Nell/Nelly - not keen. Feels too nicknamey and vaguely comical (Nelly the Elephant; ‘not on your nelly’ etc).
Fern - like; simple and fresh and botanical sounding (as opposed to a twee flower name)
Demelza - no, I get a witchy/Ugly Sister vibe to this, along the same lines as Griselda. Very clunky sounding.
Winnie - cute on a toddler but I couldn’t take an adult Winnie seriously. Would only work for me if you could skip straight from sweet preschooler to sweet elderly lady and leave out the middle part!
Nancy - very nice; has a lively, happy vibe and lots of good namesakes.